果实糖、酸组成及含量是影响风味品质的主要因素。前期研究已初步阐明梨果实糖、酸代谢及其积累特性，但果实内糖、酸如何跨膜运转到液泡内，以及糖、酸各组分间的转化等重要科学问题尚未解决。本项目拟以糖、酸积累类型各异的梨五大栽培种及其高糖/低糖、高酸/低酸的代表性品种为试材，综合应用梨基因组数据库、多组学联合分析和基因亚细胞定位及功能基因验证等技术，深入研究：1)梨果实液泡膜上调控糖、酸运转的关键基因的挖掘与筛选；2)梨果实液泡内调控糖、酸各组分间及糖与酸之间转化的关键基因的挖掘与筛选；3)调控梨果实液泡糖、酸运转与转化的关键基因的时空响应模式及功能鉴定；4)调控梨果实液泡糖、酸运转与转化的关键基因的互作蛋白筛选；5)梨果实液泡糖、酸运转与转化的分子调控网络等。研究结果将阐明调控梨果实液泡糖、酸运转与转化的分子机制，完善调控果实糖、酸性状形成的基础理论，为实现糖、酸性状的定向遗传改良奠定理论基础。

The composition and concentration of sugar & acid are of great importance for flavor quality in fruit. Previously, we had clarified the composition of sugar & acid in pear fruit as well as their accumulation characteristic. However, many important scientific questions such as how sugar & acid transport from cytoplasm into vacuole in pear fruit as well as their conversion in vacuole are still unclarified. For this, five major pear varieties cultivated in China with different accumulation characteristic and the representative varieties of high/low sugar or high/low acid content was selected as experimental material. A combination of the technology, such as pear genome database, integrated omics analysis, sub-cellular localization analysis, gene function validation and so on, was applied in order to: 1) select the key genes regulating the transportation of sugar & acid through tonoplast; 2) select the key genes regulating the convention among sugar and acid components in vacuole; 3) analyze the spatiotemporal expression characteristic and confirm the function of the key genes; 4) identify the interaction proteins of the key genes; 5) construct a molecular regulatory network on the transportation and conversion of sugar & acid in vacuole. Our study will clarify the molecular mechanism of sugar & acid transportation and conversion in vacuole of pear fruit, and consummate the basic theory on the sugar & acid formation in pear fruit, which will provide the theoretical guideline for the oriental genetic improvement of sugar & acid.